JPH05185542A - Structure with multilayer honeycomb core and manufacture thereof - Google Patents

Abstract

PURPOSE:To manufacture a product having excellent strength without using a molding die by alternately laminating a large number of honeycomb materials and a large number of fiber-reinforced plastic materials respectively and forming a multilayer honeycomb core while fast sticking a skin layer consisting of fiber-reinforced plastics on the surface of the honeycomb core. CONSTITUTION:A wing-shaped structure 1 is composed of a multilayer honeycomb core 2 and a skin layer 3 fast stuck to the surface of the honeycomb core and covering the surface. The multilayer honeycomb core 2 is formed from a large number of honeycomb materials 21-26 and a large number of fiber-reinforced plastic materials 41-45 disposed at every these layer. Each honeycomb material 21-26 is set thinly in sections, in which comparatively high strength is required, in the structure 1 at that time, and the relative quantities of the fiber-reinforced plastic materials 41-45 in the sections are augmented, thus increasing strength and rigidity. The insides of the honeycomb materials 25, 26 in the end sections (a leading edge section A and a trailing edge section B) of the structure 1 are filed with a resin 5 for reinforcement, thus further augmenting the rigidity of the end sections.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure having a multilayer honeycomb core and a method for manufacturing the same, and more particularly to a structure having a multilayer honeycomb core having good strength even at an edge portion, and such a multilayer honeycomb core structure. The present invention relates to a method capable of producing a body without using a molding die.

[0002]

2. Description of the Related Art In recent years,
For the purpose of improving the productivity by reducing the weight of a vehicle and reducing the number of constituent parts, it has been proposed to use a composite body mainly composed of plastic for a vehicle body, parts, etc., and it has been partially put into practical use.

As one of such composites, a sandwich structure composed of a pair of plastic skin layers and a core sandwiched therebetween is known. As the core, a plastic foam or a honeycomb material can be used,
For the purpose of weight reduction, it is preferable to use a honeycomb material, and it has been attempted to use such a structure for a body of an automobile or various parts.

When manufacturing a structure having such a honeycomb core, a method is generally used in which a honeycomb material is first cut into a desired shape to manufacture a honeycomb core, and then a plastic skin layer is formed on the surface of the honeycomb core. Has been adopted. However, when the honeycomb core is made of a single honeycomb material, there is a problem that the honeycomb core is deformed because it cannot withstand the molding pressure when molding the plastic skin layer. This means that the honeycomb material has a large strength in the thickness direction (axial direction of the honeycomb unit), but is relatively weak in the lateral direction (direction perpendicular to the axis of the honeycomb unit).
This is because if a force is applied in this direction, it will easily deform (crash).

Therefore, attempts have been made to increase the deformation resistance by laminating a large number of honeycomb materials. However, the strength is not sufficient and the molding pressure cannot be endured only by forming the honeycomb material into multiple layers. Therefore, there has been a problem that a molding die must be used for molding the plastic skin layer.

It is therefore an object of the present invention to provide a multi-layer honeycomb core structure which is excellent in strength and which can be manufactured without the use of a mold, and a method for manufacturing such a structure.

[0007]

As a result of earnest research in view of the above object, the present inventor has found that a plurality of honeycomb materials and a fiber-reinforced plastic material are alternately laminated to form a multilayer honeycomb material laminated body. If the honeycomb material has sufficient strength to withstand the molding pressure of the outer skin layer, and if the honeycomb material of the part where the molding pressure is large is made thinner than that in other parts, the rigidity of that part is improved. ,
The present invention was discovered by discovering that the durability of the outer skin layer against the molding pressure is further improved.

That is, the structure of the present invention has a multilayer honeycomb core formed by laminating a plurality of honeycomb materials, and the multilayer honeycomb core comprises a plurality of honeycomb materials and a fiber-reinforced plastic material alternately. An outer skin layer made of fiber reinforced plastic is in close contact with the surface of the multilayer honeycomb core.

The method of the present invention for producing a structure having a multilayer honeycomb core is (a) a plurality of honeycomb materials and a fiber-reinforced plastic material are alternately laminated to produce a multilayer honeycomb material laminate, b) The multilayer honeycomb material laminate is cut into a desired shape to produce a multilayer honeycomb core, and (c) the outer skin layer is brought into close contact with the surface of the multilayer honeycomb core.

[0010]

The present invention will be described in detail below with reference to the accompanying drawings. In the following description, a wing-shaped structure is taken as an example, but the present invention is not limited to this.

FIG. 1 is a sectional view schematically showing a structure having a multilayer honeycomb core according to an embodiment of the present invention.
The wing-shaped structure 1 is composed of (a) a plurality of honeycomb materials 21, 22, 2
3, 24, 25 and 26, and a plurality of fiber reinforced plastic materials 41, 42, 43 installed for each layer of these honeycomb materials.
The multilayer honeycomb core 2 is composed of 44 and 45, and (b) the outer skin layer 3 that adheres to and covers the surface of the multilayer honeycomb core 2. In this embodiment, each honeycomb material 21, 22,
The thicknesses of 23, 24, 25, and 26 are not the same, and the honeycomb materials 23 and 24 that form a portion to which a large molding pressure is applied are relatively thin, and the honeycomb materials 21, 22 that form the other portions.
25 and 26 are relatively thick. In this way, since the honeycomb material is thinner in the honeycomb core portion where the molding pressure is higher, a larger amount of fiber reinforced plastic material is arranged in the portion to be reinforced, and the strength (rigidity) of that portion is increased.
Will increase.

Further, in the multilayer honeycomb core structure 1, the reinforcing resin 5 is filled in the honeycomb material at the ends (the leading edge portion A and the trailing edge portion B of the blade shape). By thus filling the end portion of the structure 1 with the reinforcing resin 5, the rigidity of the end portion of the structure 1 is further increased, and the resistance to deformation during molding is improved.

An outer skin layer 3 made of a plastic material is in close contact with the outer surface of the multilayer honeycomb core 2. At this time, in order to make the surface of the multilayer honeycomb core 2 smooth, it is preferable to apply a film adhesive and then bring the outer skin layer 3 into close contact.

Next, each material constituting the structure 1 will be described. As the honeycomb materials 21 to 26, paper or those impregnated with various resins, various plastics, and honeycomb materials made of aluminum, steel, etc. can be used, but aramid fiber reinforced thermosetting resin having a large specific strength. It is preferable to use one consisting of In that case, it is preferable to use a phenol resin or the like as the thermosetting resin. As the fiber reinforced plastic materials 41 to 45 installed between the honeycomb materials, it is preferable to use reinforcing fibers impregnated with a thermosetting resin (prepreg sheet). In particular, carbon fiber, aramid fiber or the like is preferably used as the reinforcing fiber, and epoxy resin can be used as the thermosetting resin.

Further, the outer skin layer 3 of the structure 1 can be formed of various kinds of plastics, but it is particularly preferable to use fiber reinforced plastics. At this time, the prepreg sheet of fiber reinforced plastic is UD (unidirectional)
Although a sheet-like reinforcing fiber formed by randomly orienting a material, a woven fabric, a non-woven fabric, and a short fiber in two dimensions can be used, it is preferable to use a carbon fiber woven fabric in consideration of strength.
In addition, as the resin with which the above-mentioned sheet (for example, carbon fiber woven cloth) is impregnated, the resin has good moldability, can be molded into a structure having a complicated shape, and can have good rigidity. It is preferable to use a thermosetting resin.

Further, as the reinforcing resin 5 to be filled in the honeycomb material at the end portion of the multilayer honeycomb core 2, it is preferable to use a putty-like thermosetting resin, and specifically, an epoxy resin or the like is used. You can

Next, a method for manufacturing the wing-shaped structure 1 shown in FIG. 1 will be described.

First, as shown in FIG. 2, a plurality of honeycomb materials 21 to 26 having different thicknesses and fiber reinforced plastic materials 41 to 45 are used.
And are alternately laminated to produce a multilayer honeycomb material laminate 20. In this case, the thickness of each of the honeycomb members 21 to 26 is determined so that each part has sufficient rigidity when the honeycomb core 2a having the shape shown in FIG. 2 is cut out. Specifically, in the multilayer honeycomb core part where strength against the molding pressure of the outer skin layer is particularly required, the honeycomb material is thin so that a large amount of the honeycomb material is laminated, and the fiber reinforced plastic material is relatively disposed in that part. Place many in. This improves the strength of that portion.

Therefore, as the multilayer honeycomb core 2 for the wing-shaped structure 1 in this embodiment, first, the honeycomb materials 23 and 24 coming to the leading edge portion A and the trailing edge portion B, which are likely to crash, are thinned, and The fiber-reinforced plastic material is relatively increased in the part.
Also in other parts, fiber reinforced plastic material
41 to 45 are spread over almost the whole of the multilayer honeycomb core 2. Therefore, the multilayer honeycomb core 2 is entirely reinforced.

Such a multilayer honeycomb material laminate 20 can be manufactured as follows. First, as shown in FIG. 3, a plurality of L-shaped support members 11 are arranged on a support plate 10 such as an aluminum plate, and the obtained space portion D has honeycomb materials 21 to 26 having a desired thickness and fiber reinforcement. Plastic material 41 ~
Alternate 45 and. In this step, as shown in FIG. 4, a stopper plate 12 made of aluminum or the like is previously installed on the bottom surface of the space portion D, and the honeycomb materials 21 to 26 and the fiber reinforced plastic materials 41 to 45 are laminated thereon. Good to do. And the desired multilayer honeycomb material laminate
When 20 is obtained, another stopper plate 12 is placed on the laminated body 20. Here, the L-shaped support member 11 protects the honeycomb from the pressure applied to the side surface of the laminate 20 in the subsequent molding process,
It functions to prevent deformation (crush) of the honeycomb. Further, the upper and lower stopper plates 12, 12 serve to hold the laminated body 20 in a desired shape.

Next, as schematically shown in FIG. 5, the laminated body 20 is placed on the metal supporting plate 10, and the porous release film 13 for preventing resin outflow and the air permeability are placed on the laminated body 20. The breather mat 14 and the bagging film 15 are set in order, and the sealing material 16 is provided at the end of the bagging film 15.
Seal with. In such a bagging state, heating and pressing are performed to cure the multilayer honeycomb material laminate 20.

The heating and pressurizing conditions in the above curing treatment are as follows:
Depending on the resin used, when epoxy resin is used for the fiber reinforced plastic material (prepreg), the heating conditions are as shown in FIG. 6, and the pressurizing conditions are about 1 to 4 kg / cm ^2. And

The multilayer honeycomb material laminate 20 obtained by the above method is cut out into a desired shape, and the multilayer honeycomb core 2 is obtained.
And For cutting the multilayer honeycomb material laminate 20, a numerically controlled cutting tool such as an end mill or a cup cutter can be used. When cutting, the multilayer honeycomb material laminate 20 is fixed on the base plate 17 with a double-sided adhesive tape. At this time, if the fiber-reinforced plastic material 46 is arranged on the lower surface of the multilayer honeycomb material laminate 20 in advance, the multilayer honeycomb material laminate 20 can be favorably fixed to the base plate 17. Note that FIG. 7 shows a state in which the multilayer honeycomb material laminate 20 is cut using the cup cutter 19.

Thus, the multilayer honeycomb material laminate 20 is obtained.
Cutting the upper half of the intermediate product 2 as shown in Fig. 8 (a)
We get 0a. Next, as shown in FIG. 8 (b), the intermediate product 20 is attached to the support member 38 having a recess corresponding to the cut portion.
A is placed and the opposite side (lower half) is cut to obtain a wing-shaped honeycomb core 2.

Next, at the portion (leading edge portion A and trailing edge portion B) where reinforcement of the obtained wing-shaped honeycomb core 2 is required, as shown in FIG. 9, the reinforcing resin 5 is added to the honeycomb material. To fill.

Further, in this embodiment, the film-like adhesive 6 is adhered to the surface of the multilayer honeycomb core 2 for smoothing. As the film adhesive material 6, a material made of an epoxy resin can be used.

Next, as shown in FIG. 10, the end ribs 7, 7 are adhered to the planar end face of the multilayer honeycomb core 2.
As the end ribs 7, 7, it is preferable to use a hard plate made of a fiber reinforced plastic material. The use of such end ribs improves the smoothness and rigidity of the end surface.

The outer skin layer 3 is laid up on the surface of the multilayer honeycomb core 2 to which the end ribs 7, 7 are adhered. in this case,
As shown in FIG. 11, the outer skin layer 3 (only the upper half is shown) is preferably adhered so that the end ribs 7 are wound (or the end portions of the outer skin layer 3 are placed on the end ribs 7). As the outer skin layer 3, a prepreg sheet of the fiber-reinforced thermosetting resin as described above can be used, but it is preferable to use a plurality of prepreg sheets stacked together. When the prepreg sheet is a woven cloth impregnated with a thermosetting resin, it is preferable that the prepregs are superposed so that the fiber directions of the woven cloth are different, and the outer skin layer 3 is imparted with an isotropic property.

The multilayer honeycomb core 2 having the outer skin layer 3 laid up is debulked and then heat-pressed. At the time of this heat-press molding, in order to impart surface smoothness to the final product, as shown in FIG. 12, the outer skin layer 3 is surrounded by a pressure plate 30. As a pressure plate, metal foil such as iron foil (thickness 0.1 mm)
Can be used. To perform heat and pressure molding, a porous release film 31, a breather mat 32, and a bagging bag 3 are provided around the pressure plate 30.
3 and 3 are sequentially set, and the inside of the bagging bag 33 is depressurized. In that state, the outer skin layer 3 is heat-cured. The heating and pressurizing conditions are preferably the conditions illustrated in FIG.

Wing-shaped structure 1 obtained by the above steps
Shall be trimmed at the edges, etc. as necessary to obtain a finished product.

The present invention will be described in more detail by the following specific examples. Example 1 A honeycomb material made of aramid fiber-reinforced thermosetting resin having a thickness of 3/16 inch, 3/8 inch, and 1/2 inch was used, and carbon was used as a fiber-reinforced plastic material arranged between these honeycomb materials. The fiber-reinforced thermosetting resin prepreg sheet is used, and the supporting mold shown in FIGS.
A multilayer honeycomb material laminate having the shape shown in was formed. This multilayer honeycomb material laminate was cured by the apparatus shown in FIG. 5 and the temperature conditions shown in FIG.

The multilayer honeycomb material laminate thus cured was cut with an end mill and a cup cutter to obtain a blade-shaped multilayer honeycomb core. As shown in FIG. 9, a reinforcing resin (epoxy resin compound) was filled in the honeycomb units at the front end and the rear end of this multilayer honeycomb core. Further, the surface of the multilayer honeycomb core was covered with a film adhesive made of epoxy resin.

As shown in FIG. 10, end ribs made of carbon fiber and epoxy resin were fixed to the planar side ends of the obtained multilayer honeycomb core. Next, the outer skin layer was laid up and covered with the pressure plate 30. As the outer skin layer, 1 ply of a prepreg having a thickness of 0.15 mm and 2 plies of a prepreg sheet having a thickness of 0.3 mm from the inside (the orientation direction of the fibers are deviated by 45 °), and 0.1
A 4-layer structure in which one ply of a prepreg sheet having a thickness of 5 mm was overlaid was used.

After debulking in order to bring the outer skin layer into close contact, the multilayer honeycomb core 2 together with the pressure plate was placed in a bagging bag for bagging, and then cured by heating as it was. The heat curing process conditions at this time are shown in FIG.
It was as shown in 3.

The end face of the obtained structure was trimmed to obtain a final molded product. The final molded product was far lighter than the conventional urethane foam wing structure having a skin, spar, or rib structure, and also had good rigidity and strength.

[0036]

As described above in detail, the structure of the present invention having a multilayer honeycomb core has excellent strength and can be used as various parts including automobile parts. Also,
According to the method of the present invention, the outer skin layer can be molded without deformation without using a molding die, and therefore the manufacturing cost is significantly reduced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a structure having a multilayer honeycomb core according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of a multilayer honeycomb material laminated body for manufacturing a multilayer honeycomb core.

FIG. 3 is a perspective view showing an example of a support die used for forming a multilayer honeycomb material laminate.

4 is a partial cross-sectional view showing a state in which a laminated body made of a honeycomb material and a fiber reinforced plastic material is installed on the support die shown in FIG.

FIG. 5 is a schematic cross-sectional view showing an example of an apparatus for press-heating and curing a laminate made of a honeycomb material and a fiber-reinforced plastic material.

FIG. 6 is a graph showing an example of heating conditions for heating and curing a laminate made of a honeycomb material and a fiber-reinforced plastic material.

FIG. 7 is a perspective view showing a state in which the multilayer honeycomb material laminate is being cut by a cup cutter.

[Fig. 8] Fig. 8 is a schematic cross-sectional view showing a cut multilayer honeycomb formed material, (a) shows a multilayer honeycomb material laminate obtained by cutting the upper half, and (b) is fixed to a support member to Fig. 2 shows a multilayer honeycomb material laminated body in which a portion is cut to form a blade shape.

FIG. 9 is a cross-sectional view showing a state in which a multilayer honeycomb core is formed by using a multilayer honeycomb material laminate formed into a blade shape.

[Fig. 10] Fig. 10 is a perspective view showing a state in which end ribs are attached to flat end portions of a multilayer honeycomb core.

FIG. 11 is a perspective view showing a state in which an outer skin layer is provided on the surface of the multilayer honeycomb core.

[Fig. 12] Fig. 12 is a schematic cross-sectional view showing a state in which a multilayer honeycomb core having an outer skin layer is pressure-molded in a bagging bag.

[Fig. 13] Fig. 13 is a graph showing an example of temperature conditions and pressure conditions when heat curing a multilayer honeycomb core having an outer skin layer mounted thereon.

[Explanation of symbols]

 1 Multilayer Honeycomb Core Structure 2 Multilayer Honeycomb Core 3 Skin Layer 5 Reinforcing Resin 6 Film Adhesive 7 End Rib 10 Metal Support Plate 11 L-Shaped Support Member 12 Stopper Plate 13, 31 Porous Release Film 14, 32 Breather Mat 15 Bagging Film 16 Sealant 19 Cup cutter 20 Multi-layer honeycomb material Laminate 21-26 Honeycomb material 30 Pressure plate 33 Bagging bag 38 Support member 41-46 Fiber reinforced plastic material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kouji Kotani 1-4-1 Chuo, Wako-shi, Saitama Inside the Honda R & D Co., Ltd. (72) Inventor Kazuhiro Tachibana 4-1-1 Chuo, Wako, Saitama Stock Company Honda Technical Research Institute

Claims (7)

[Claims] 1. A structure having a multilayer honeycomb core formed by stacking a plurality of honeycomb materials, wherein the multilayer honeycomb core is formed by alternately stacking a plurality of honeycomb materials and a fiber reinforced plastic material. A structure characterized in that an outer skin layer made of fiber reinforced plastic is in close contact with the surface of a honeycomb core. 2. The structure according to claim 1, wherein the plurality of laminated honeycomb materials are laminated while changing the thickness according to the strength required for each part of the structure, A structure characterized in that a relatively large amount of thin honeycomb material is laminated in a portion where relatively high strength is required in the body, thereby increasing the relative amount of the fiber-reinforced plastic material in this portion. 3. The structure according to claim 1, wherein a reinforcing resin is filled in the honeycomb material at the end of the multilayer honeycomb core. 4. A method for producing a structure having a multilayer honeycomb core, comprising: (a) alternately laminating a plurality of honeycomb materials and a fiber reinforced plastic material to produce a multilayer honeycomb material laminate; ) The multilayer honeycomb material laminate is cut into a desired shape to produce a multilayer honeycomb core, and (c) a structure having a multilayer honeycomb core characterized in that an outer skin layer is adhered to the surface of the multilayer honeycomb core. Manufacturing method. 5. The method according to claim 4, wherein the honeycomb material in a portion to which a large forming pressure is applied at the time of forming the outer skin layer is made thinner than the honeycomb material in other portions, and thereby the strength in a portion to which a large forming pressure is applied. A method characterized by improving. 6. The method according to claim 4 or 5, wherein
Before adhering the outer skin layer to the multilayer honeycomb core,
A method comprising filling a reinforcing resin into a honeycomb material at an end of the multilayer honeycomb core. 7. The method according to claim 4, wherein a film-like adhesive for smoothing is brought into close contact with the surface of the multilayer honeycomb core, and then an outer skin layer is brought into close contact therewith, and a substantial pressure plate is used to adhere the outer skin layer. The method is characterized in that heating and pressurizing are performed in a state of being covered without any gap.